tjson: Implement datetime (#1027)

Closes #905.

Co-authored-by: Alexey Palazhchenko <alexey.palazhchenko@ferretdb.io>

integration/shareddata/shareddata.go

@@ -47,11 +47,11 @@ func AllProviders() []Provider {
 		Binaries,
 		ObjectIDs,
 		Bools,
-		// DateTimes, TODO https://github.com/FerretDB/FerretDB/issues/905
+		DateTimes,
 		// Nulls, TODO https://github.com/FerretDB/FerretDB/issues/906
 		// Regexes, TODO https://github.com/FerretDB/FerretDB/issues/911
 		Int32s,
-		// Timestamps, TODO https://github.com/FerretDB/FerretDB/issues/905
+		// Timestamps, TODO https://github.com/FerretDB/FerretDB/issues/1007
 		Int64s,
 		// Unsets, TODO https://github.com/FerretDB/FerretDB/issues/1023
 

internal/tjson/datetime.go

@@ -0,0 +1,72 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tjson
+
+import (
+	"bytes"
+	"encoding/json"
+	"time"
+
+	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+)
+
+// dateTimeType represents BSON UTC datetime type.
+type dateTimeType time.Time
+
+// tjsontype implements tjsontype interface.
+func (dt *dateTimeType) tjsontype() {}
+
+// String returns formatted time for debugging.
+func (dt *dateTimeType) String() string {
+	return time.Time(*dt).Format(time.RFC3339Nano)
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (dt *dateTimeType) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, []byte("null")) {
+		panic("null data")
+	}
+
+	r := bytes.NewReader(data)
+	dec := json.NewDecoder(r)
+
+	var o time.Time
+	if err := dec.Decode(&o); err != nil {
+		return lazyerrors.Error(err)
+	}
+
+	if err := checkConsumed(dec, r); err != nil {
+		return lazyerrors.Error(err)
+	}
+
+	*dt = dateTimeType(time.UnixMilli(o.UnixMilli()).UTC())
+
+	return nil
+}
+
+// MarshalJSON implements tjsontype interface.
+func (dt *dateTimeType) MarshalJSON() ([]byte, error) {
+	res, err := json.Marshal(time.UnixMilli(time.Time(*dt).UnixMilli()).UTC())
+	if err != nil {
+		return nil, lazyerrors.Error(err)
+	}
+
+	return res, nil
+}
+
+// check interfaces
+var (
+	_ tjsontype = (*dateTimeType)(nil)
+)

internal/tjson/datetime_test.go

@@ -0,0 +1,62 @@
+// Copyright 2021 FerretDB Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tjson
+
+import (
+	"testing"
+	"time"
+
+	"github.com/AlekSi/pointer"
+)
+
+var dateTimeTestCases = []testCase{{
+	name:   "2021",
+	v:      pointer.To(dateTimeType(time.Date(2021, 11, 1, 10, 18, 42, 123000000, time.UTC))),
+	schema: dateTimeSchema,
+	j:      `"2021-11-01T10:18:42.123Z"`,
+}, {
+	name:   "unix_zero",
+	v:      pointer.To(dateTimeType(time.Unix(0, 0).UTC())),
+	schema: dateTimeSchema,
+	j:      `"1970-01-01T00:00:00Z"`,
+}, {
+	name:   "0",
+	v:      pointer.To(dateTimeType(time.Date(0, 1, 1, 0, 0, 0, 0, time.UTC))),
+	schema: dateTimeSchema,
+	j:      `"0000-01-01T00:00:00Z"`,
+}, {
+	name:   "9999",
+	v:      pointer.To(dateTimeType(time.Date(9999, 12, 31, 23, 59, 59, 999000000, time.UTC))),
+	schema: dateTimeSchema,
+	j:      `"9999-12-31T23:59:59.999Z"`,
+}, {
+	name:   "EOF",
+	schema: stringSchema,
+	j:      `{`,
+	jErr:   `unexpected EOF`,
+}}
+
+func TestDateTime(t *testing.T) {
+	t.Parallel()
+	testJSON(t, dateTimeTestCases, func() tjsontype { return new(dateTimeType) })
+}
+
+func FuzzDateTime(f *testing.F) {
+	fuzzJSON(f, dateTimeTestCases)
+}
+
+func BenchmarkDateTime(b *testing.B) {
+	benchmark(b, dateTimeTestCases)
+}

internal/tjson/schema.go

@@ -267,8 +267,7 @@ func valueSchema(v any) (*Schema, error) {
 	case bool:
 		return boolSchema, nil
 	case time.Time:
-		// return dateTimeSchema, nil
-		return nil, lazyerrors.Errorf("%T is not supported yet", v)
+		return dateTimeSchema, nil
 	case types.NullType:
 		return nil, lazyerrors.Errorf("%T is not supported yet", v)
 	case types.Regex:

internal/tjson/tjson.go

@@ -22,6 +22,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"time"
 
 	"github.com/AlekSi/pointer"
 
@@ -70,8 +71,8 @@ func fromTJSON(v tjsontype) any {
 		return types.ObjectID(*v)
 	case *boolType:
 		return bool(*v)
-	// case *dateTimeType:
-	// 	return time.Time(*v)
+	case *dateTimeType:
+		return time.Time(*v)
 	// case *nullType:
 	// 	return types.Null
 	// case *regexType:
@@ -104,8 +105,8 @@ func toTJSON(v any) tjsontype {
 		return pointer.To(objectIDType(v))
 	case bool:
 		return pointer.To(boolType(v))
-	// case time.Time:
-	// 	return pointer.To(dateTimeType(v))
+	case time.Time:
+		return pointer.To(dateTimeType(v))
 	// case types.NullType:
 	// 	return pointer.To(nullType(v))
 	// case types.Regex:
@@ -168,7 +169,11 @@ func Unmarshal(data []byte, schema *Schema) (any, error) {
 			var o objectIDType
 			err = o.UnmarshalJSON(data)
 			res = &o
-		case UUID, DateTime:
+		case DateTime:
+			var o dateTimeType
+			err = o.UnmarshalJSON(data)
+			res = &o
+		case UUID:
 			fallthrough
 		case Double, Float, Int64, Int32:
 			fallthrough

internal/tjson/tjson_test.go

@@ -317,6 +317,8 @@ func unmarshalJSON(v tjsontype, j string) (bool, error) {
 		err = v.UnmarshalJSON([]byte(j))
 	case *boolType:
 		err = v.UnmarshalJSON([]byte(j))
+	case *dateTimeType:
+		err = v.UnmarshalJSON([]byte(j))
 	case *int32Type:
 		err = v.UnmarshalJSON([]byte(j))
 	case *int64Type: